Water heating unit



July 2, 1946. M. DOERNER WATER HEATING UNIT Filed Dec. 29, 1944 INVENTOR MAX DOERNER ATTORNEY Patented July 2, 1946 UNITED STATES PATENT JOFFICE 7 2,403,173 I WATER HEATI N G UNIT f Max Doerner} NewYork, N. T Application December 29, 1944, Serial No. 570,312

1 Claim. (Cl. 122-250) This invention relates to water heating coils for use with steam boilers, gas boilers, and other appliances Where it is desired to preheat the water by waste heat to increase the efficiency of the apparatus in connection with which the coils are employed and is an improvement over the heating unit disclosed in Patent #1,860,495, issued to me on May 31, 1932.

It is one of the principal objects to provide a heating coil unit adapted to be used with various types of heaters;

Another object is to make a unit of this character easily applicable to various kinds of heaters;

A further object is to attain the desired purpose with a coil which is economically manufactured and which operates at a high efliciency;

Still further objects will become apparent as the nature of the invention is better understood after a perusal of the following specification.

The invention is illustrated by the accompanying drawing in which a preferred embodiment of the invention is shown, and in which Fig. 1 is a plan view of the coil unit; and

Fig. 2 is an elevational view of the same, partly in section.

In both of these figures the conventional design of a steam boiler is shown in dotted lines to indicate the manner in which the unit is attached to apparatus of that kind.

I is the outer cylindrical shell of such a boiler, having a water and steam space H formed by a top wall l2, a bottom wall l3, and a cylindrical inner shell I4 defining a waste gas passage l5 communicating with a fire box l6 below the passage and the bottom wall l3. The upper ends of shell ID are extended above the top wall l2 and are adapted to receive a dome I! having a flue connection at 8. Only the vital elements of a boiler have been described so far to illustrate the application of the invention which is in no way limited to any particular type.

Referring now to the essential parts of the invention, I9 is the inlet end of a heating coil having a union connection 20 for ready application to a water supply pipe. 2| are a plurality of coils horizontally disposed on top of top wall |2 of the steam space of the boiler. The inner end of coils 2| is bent downwardly at 22 and is coiled downwardly alongside the walls [4 of firebox Hi to form an outer coil 23. The bottom end of this coil is bent upwardly at 24 to form an upwardly extended coil 25 within the convolutions of coil 2 3. The top end of coil 25 is bent over at 2'6 and passes over coils 2| and extends outwardly of the boiler shell to terminate in an outlet end 21 having a union connection 28 which is attached to a water outlet pipe.

In operation, water is admitted into the heat-, ing coil at H], whence it first passes through the plurality of coils 2| ,on top of the top wall I2 of the steam space of the boiler. These coils 2| absorb a good deal of heat from the wall l2. The water then passes downwardly into the outer coil 23 which extends through the waste gas passage l5 and is heated further by the gases arising from the firebox I6. Then the water is led upwardly again through inner coil 25 to be further heated, and finally through union connection 21 to a boiler feed pipe shown in dotted lines in Fig. 2.

During this travel the water is thus heated in three different stages, firstly, in the horizontally disposed coils, above and immediately adjacent the hot top wall of the boiler, secondly, in the outer coil located in the waste gas passage, and.

, thirdly, in the inner coil also located in this pas- This results in a preheating of water by v sage. otherwise wasted heat which greatly increases the efiiciency of the boiler or other apparatus to which the coil unit is applied,

The union connections at both the inlet and outlet ends of the coil make application and removal of the coil particularly simple.

While I have shown the invention applied to a steam boiler, as stated above, this is for illustrations sake only. The heating coil unit can be applied to gas ovens, furnaces, or any other apparatus where it is desired to heat, respectively, preheat the water effectively. It can also be employed in connection with a separate gas heater used only to create heat to raise the temperature of the water in the coil, when the shape of the gas heater need only be made so as to Instead of completing a plurality of circular coils and then connecting them to the downward ly and upwardly extending center coils to connect the center coils directly to a boiler feed pipe, I may provide a plurality of half coils on top only to connect to the center coils and then connect the outlet of the center coils to another plurality. of half coils on top which then connects with the boiler feed pipe.

The center coils instead of being made of one piece with the circular top coils, may by union and generation of steam, a water heating" unit t.

of horizontally 'clisposed inlet, a plurality'of'vercomprising a plurality coils of pipe having an proportions anda chamber around said duct for water];

tically descending coils of pipe connected to said horizontally disposed coils, and a plurality of vertically ascending coils of pipe concentric with, and forming the continuation of the lowest coil of, said plurality of coils ofdescending pipe, said vertically ascending coils of pipe having an outlet, and a union connection at, respectively, said inlet and said outlet, said inlet being connected to the feed water supply for the boiler, and said outlet being connected to the bottom of said chamber, the said horizontally disposed coils being disposed on top of said chamber forming a support for the unit, said descending and ascending coils'being located in said waste gas passage.

MAX DOERNER. 

